Guided Practice

The number line shows the location of your house (H), the library (L), and the school (S).

If the school is located at 0, what are the locations of your house and the library?You can count on the number line to determine the locations.

Your house is 6 units to the left 0, so its location is –6. The library is 8 units to the left of 0, so its location is –8.What is the opposite of –4? What is the opposite of 8?

You can use a negative sign to show the opposite of a number.

The opposite of –4 can be written as

–(–4), which is the same as 4.

The opposite of 8 can be written as –8.

If Barney's location was called 0 on the number line, then Alicia would be at .

If Barney's location was called 0 on the number line, then Clara would be at .

If Clara's location was called 0 on the number line, then Alicia would be at .

If Clara's location was called 0 on the number line, then Barney would be at .

The opposite of 1 is .

The opposite of –2 is .

The opposite of 0 is .

If your house was located at 0, then the school would be at .

If your house was located at 0, then the library would be at .

This number line shows the locations of the park (P), the mall (M), and your house (H). The interval on the number line is 1.

If the mall is at 0 on the number line, then the park would be at .

If your house is at 0 on the number line, then the park would be at .

This number line shows the temperatures in 3 different cities. The interval is 1.

If it is 0 degrees in Centertown, then it is degrees in HotCity.

If it is 0 degrees in HotCity, then it is degrees in Middleville.

Write each opposite. Use a hyphen for a negative sign. Use parentheses () for the opposites of negative numbers.

Opposite of 10:

Opposite of –5:

Write each opposite. Use a hyphen for a negative sign. Use parentheses () for the opposites of negative numbers.

Opposite of –11:

Opposite of 11: –

Write each opposite. Use a hyphen for a negative sign. Use parentheses () for the opposites of negative numbers.

Opposite of –8:

Opposite of –9:

I'm thinking of a number from –10 to 10 . . .

Try to guess the number. If you think it's less than –1, press the less-than symbol (<) and enter -1 in the box. Then press Enter or Return. The numbers less than –1 will be highlighted. If the mystery number is less than –1, you will see a blue highlight. If the mystery number is not less than

–1, you will see an orange highlight.

Keep entering guesses to close in on the mystery number. When you think you've got it, click on the circle above the number. Correct answers are worth 1 point, BUT incorrect answers are worth

–3 points. Guesses don't cost you anything.

Earn 20 points to pass.

Were you surprised to see the expression n + 1 to the left of 0? Enter some different values of n that make n + 1 less than 0.

n = or

n = or

n = or

. . .

If n is equal to –3, then n + 1 is equal to –2. What is the opposite of n + 1 in that case?

–(n + 1) =

If n is equal to –10, what is the opposite of n + 1?

–(n + 1) =

If n is equal to 4, what is the opposite of n – 1?

–(n – 1) =

Write your answer as a fraction in simplest form with a slash (/).

If n is equal to –(1/3+ 3), write the opposite of n.

–n =

Write your answer as a fraction in simplest form with a slash (/).

If the opposite of n is equal to 1/5+2/5, what is n?

n =

If n is equal to 0.05, what is the opposite of n + 1?

–(n + 1) =

If –n is equal to 5/3–5/3, what is –(–n), or the opposite of –n?

–(–n) =

If n is equal to 0.53, what is the opposite of

n – 0.5?

–(n – 0.5) =

Write your answer as a fraction in simplest form with a slash (/).

If –n is equal to –1/2, what is n?

n =

Write your answer as a fraction in simplest form with a slash (/).

If n is equal to 2/3–1/6, what is the opposite of

n + 1?

–(n + 1) =

If n is equal to 10.3, what is the opposite of n – 1?

–(n – 1) =

If –n is equal to 1.5, what is –n + 1?

–n + 1 =

Write your answer as a fraction in simplest form with a slash (/).

If –n is equal to 4/5, what is –n + 1?

–n + 1 =

Write your answer as a positive or negative whole number.

If 8/3 + 4/3 is equal to n, what is –(n – 1)?

–(n – 1) =

If 4 is equal to n, what is –(n + 1)?

–(n + 1) =

When you know the location of 0 on any number line, then you can know the locations of positive and negative numbers. Consider this number line. Each tick mark is separated by 1.

You can tell that the value at A is –3, the value at B is 2, the value at C is 3, and the value at D is

–2. But when we change the location of 0, the other values must change too.

Every whole number has an opposite. For example, the opposite of 1 is –1. You often see the – sign used with numbers less than zero, but this sign does not mean "less than zero." It means "the opposite of." Here are some values and their opposites.

- –5 → 5, or –(–5)
- 0 → 0
- 3 → –3
- –n → n, or –(–n)

Determine the value at each location on the bottom number line.

A =

B =

C =

D =

Write the opposite of each number.

7 →

–3 →

Write the opposite of each number.

2 →

–9 →

Write the opposite of each number.

14 →

–21 →

Write the opposite of each number.

0 →

–8 →

Write the opposite of each number.

–99 →

–49 →

Write the opposite of each number.

80 →

50 →

Write the opposite of each number.

–5 →

6 →

Write the opposite of each number.

–42 →

42 →

Write the opposite of each number.

–24 →

24 →

Determine whether or not each question is a statistical question. Answer with **is** or **is not**.

How many people are in my class?

This a statistical question.

Determine whether or not each question is a statistical question. Answer with **is** or **is not**.

At what time do most people eat lunch?

This a statistical question.

Determine whether or not each question is a statistical question. Answer with **is** or **is not**.

How much money do major-league baseball players earn in a year?

This a statistical question.

Determine whether or not each question is a statistical question. Answer with **is** or **is not**.

How long do elephants live?

This a statistical question.

Determine whether or not each question is a statistical question. Answer with **is** or **is not**.

What is the tallest roller coaster in the world?

This a statistical question.